Improvement



W. H. LAMB.

Watch Escapement. No. 70,724. Patented Nov. 12, 1867.

UNITED STATES PATENT OFFICE.

WILLIAM H. LAMB, OF SAN FRANCISCO, CALIFORNIA.

IMPROVEMENT ifik'JATCH-ESCAPEMENTS.

Specification forming part of Letters Patent No. 70,724, dated November 12, 1867.

To all whom it may concern:

Be it known that 1, WILLIAM H. LAMB, of San Francisco, county of San Francisco, State of California, have invented a certain new and useful Improvement in Escapements for Watches and Clocks; and I do hereby declare the following description and accompanying drawings are sufficient to enable any person skilled in the art or science to which it most nearly appertains to make and use my said invention or improvement without further invention or experiment.

Myinvention relates to the escapements used for time-pieces, and its object is to provide an improvementof such a nature that an impulse is given to the balance-wheel at each vibration by passing the teeth of the escape-wheel on each side of the balance-staff.

It also consists in unlocking the teeth of the escape-wheel by means of a pin on the balance-staff coming in contact with the end of the detent-lever,the whole forming a perfectly free escapement.

To effect the first I attach two wheels to the same staff, one being much smaller and placed higher up than the other. The smaller one has its escape-teeth on the outer circumference of the rim, while the larger one has these on the inner circumference. The staff of the balancewheel passes up between these two sets of teeth, and carries two notched rollers so constructed that the smaller wheel acts upon one side of one roller on one vibration, while the outer one acts upon the opposite side of the other roller for the reverse motion. A small pin, also attached to the balance-staff, comes in contact with the end of a detent-lever at each vibration and moves it back. This lever carries a pin, which is .thus thrown out of contact with the detent-teeth on the outside of the larger wheel, thus allowing the wheel to rotate.

To more fully explain my invention reference is had to the accompanying drawings, formingpart of this specification, of which- Figure 1 is a side elevation, with a section of plate and lower escape-wheel. Fig. 2 is a plan with balance-wheel removed. Fig. 3 is a view with the rollers separated to show their action clearly. Fig. 4 is an enlarged view of the balance-staff pin and rollers, also the end of the detent-lever with its disengaging-pin. Fig. 5 is a top view of the detent-lever and the pin on the balance-staff.

Similar letters in each of the drawings indicate like parts.

A is the upper plate of a time-piece, having attached to it the necessary bearings for the support of the different parts of the machinery. B is the balance-wheel and O its operating hair spring.

The escapement consists of two wheels, D and E,both attached to the same staff, F. The wheel D is made smaller than E to allow the balance-staff e to stand between the two, this staff being supported by a plate, a, which is attached to A and bent down over the inner circumferenceofthewheelE. Inordertoallow this, the arms of E are bent, as shown, so that their plane is some distance below the plane of the rim. The wheel D is placed above E, so as to admit of the two rollers I) and 0 being used, one above the other, on the balancestaff. These rollers are notched on opposite sides, the notch in c engaging the impulseteeth of E, while the notch in 11 operates in the impulse-teethofD. Thedetent-lever(lvibrates about a staff on the plate A, and has at the end a pin, g, projecting downward, which is kept in contact with the detent-teeth on E by the hair-spring h. A pin or arm, 2', is attached to the balance-start just below the roller 1), which comes in contact with the end of the detent-lever at each vibration of the balancewheel, moving it back, and thus disengaging the pingfrom the detent-teethnof the wheel E.

I will now proceed to describe its operation.

The spring or other motive power being applied through the proper train of wheel-works, an impulse'will be given by one of the wheels D or E, beginning with D, and, supposing one detent-tooth, a, unlocked, the impulse-tooth on D engages the notch in the roller 1) and gives the balance-wheel B an impulse to the right. As the wheel completes its vibration in this direction the pin I pushes the detent-lever back until the pin g is disengaged, thus allowing another detent-tooth to pass. This brings an impulse-tooth on the outer wheel, E, to bear upon the notched roller 0, and the notch being upon the opposite side of the staff from that in b, an impulse is given to the left, and so on alternately. By this construction, when well made, it will be impossible to stop the balancewheel at a point where it will not start itself, and nothing can make it gallop, for if the balance-wheel should vibrate so far as to unlock the detent-tooth a second time the impulsetooth would be caught by the side of the roller and could not pass until the return of the notch in the roller. The detent-lever is also bent so that the pin I operates on the end of it and from each side.

Having thus described my invention, what I claim, and desire to secure by Letters Patent,

escape-wheel by the liberating-pin ion the halanoe-stafi coming in contact with the end of the detent-lever 01, substantially as described. 3. The combination of the wheels D and E, operating on each side of the balance-staff by means of the notched rollers 11 and c, or their equivalent, and the liberating-pin 1;, operating on the end of the detent-lever d and the pin 9, the whole operating as and for the purposes herein specified and described.

In witness whereof I have hereunto set my hand and seal.

WM. H. LAMB. [L. s.] Witnesses G. W. M. SMITH, J. L. BooNE. 

